|PROSITE documentation PDOC51710|
The P-loop (see <PDOC00017>) guanosine triphosphatases (GTPases) control a multitude of biological processes, ranging from cell division, cell cycling, and signal transduction, to ribosome assembly and protein synthesis. GTPases exert their control by interchanging between an inactive GDP-bound state and an active GTP-bound state, thereby acting as molecular switches. The common denominator of GTPases is the highly conserved guanine nucleotide-binding (G) domain that is responsible for binding and hydrolysis of guanine nucleotides.
Within the translation factor-related (TRAFAC) class of P-loop GTPases, the OBG family comprises a group of high-molecular mass GTPases conserved from bacteria to eukaryotes. The OBG family consists of :
The OBG-type G domain has a mononucleotide binding fold typical for the P-loop NTPases. A six-stranded mostly parallel β-sheet is flanked by α-helices on both sides (see <PDB:1JAL>). The OBG-type G domain contains five characteristic sequence motifs, termed G1-G5, involved in nucleotide binding and hydrolysis. The G1/Walker A motif (GXXXXGK(S/T)), also referred to as P-loop, helps to position the triphosphate moiety of the bound nucleotide. The G2 (X(T/S)X) and G3/Walker B (hhhDXXG) motifs are involved in the coordination of a Mg(2)+ ion that is required for nucleotide binding and hydrolysis. Specificity in nucleotide binding is conferred by the G4 motif, which has a (N/T)KXD signature in guanine nucleotide binding P-loop NTPases. The G5 motif ((T/G)(C/S)A) supports guanine base recognition [2,3,5,6].
The profile we developed covers the entire OBG-type G domain.Last update:
March 2014 / First entry.
PROSITE method (with tools and information) covered by this documentation:
|1||Authors||Leipe D.D. Wolf Y.I. Koonin E.V. Aravind L.|
|Title||Classification and evolution of P-loop GTPases and related ATPases.|
|Source||J. Mol. Biol. 317:41-72(2002).|
|2||Authors||Buglino J. Shen V. Hakimian P. Lima C.D.|
|Title||Structural and biochemical analysis of the Obg GTP binding protein.|
|3||Authors||Kukimoto-Niino M. Murayama K. Inoue M. Terada T. Tame J.R.H. Kuramitsu S. Shirouzu M. Yokoyama S.|
|Title||Crystal structure of the GTP-binding protein Obg from Thermus thermophilus HB8.|
|Source||J. Mol. Biol. 337:761-770(2004).|
|4||Authors||Ishikawa K. Azuma S. Ikawa S. Morishita Y. Gohda J. Akiyama T. Semba K. Inoue J.i.|
|Title||Cloning and characterization of Xenopus laevis drg2, a member of the developmentally regulated GTP-binding protein subfamily.|
|5||Authors||Teplyakov A. Obmolova G. Chu S.Y. Toedt J. Eisenstein E. Howard A.J. Gilliland G.L.|
|Title||Crystal structure of the YchF protein reveals binding sites for GTP and nucleic acid.|
|Source||J. Bacteriol. 185:4031-4037(2003).|
|6||Authors||Koller-Eichhorn R. Marquardt T. Gail R. Wittinghofer A. Kostrewa D. Kutay U. Kambach C.|
|Title||Human OLA1 defines an ATPase subfamily in the Obg family of GTP-binding proteins.|
|Source||J. Biol. Chem. 282:19928-19937(2007).|